Method of and apparatus for determining the drying time of substances



Dec. 12, 1933. A M, PARKS 1,938,975

METHOD OF AND APPARATUS FOR DETERMINING THE DRYING TIME OF SUBSTANCES Filed Aug. 6, 1930 22 /.5 /9 /2 0 2 N K j 2/ /.5 20 22 m /9 Q l6 7 k/ r (H H6. 2. V

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Patented Dec. 12, 1933 MUNITED LSTATI-ES H 1,938,975 METHOD 0F AND APPARATUS FoR DE-f TERMINING .THE DRYING TIME OF SUB- STANCES 1 Alfred M. Parks, Philadelphia, Pa..- Application August ,.1930f's 1-ial No. 473,503". zclaims. (01. 73-51) I My invention comprises a method of testing'the time of drying of various substances, such as ,varnishes, paints, enamels, inks, printing inks, oils and the like. 1

My method consists of coating test strips with a layer of the material to be tested ofuniform thickness. This is done by applying the material to be tested to the strip with a spatula and then passing a roller without pressure, other than the weight of the roller, over the surface of the strip thereby distributing the material to be tested uniformly over'the surface of the strip and to a uniform depth. The test strips covered with the wet material to be tested are then placed in a rack, and av band, such as a band of corrugated rubber or web of linen or cotton cloth, is then placed around a roller in such a manner that the roller in passing along the rack over the strips impresses the band into the wet material to be tested on the strips. If desired a powder, such as flour, chalk, talc I or pigment may be placed upon the band and be thereby impressed at spaced intervals into the material to be tested.

Means are provided, such as a clockwindlass, for

drawing the rollerat a slow, uniform speed over the test strips. At the completion of a suitable time for testing, for example, twenty-four hours,

' the roller will have completed a trip over the test strips and upon removal of the roller and the band the material to be tested on the test strips will be found to have a series; of indentations therein. If powder has been used these indentations will be marked by the powder used. In

case powder has been used the test strips are then washed with water and the loose powder removed by a light pressure. or that which has been applied to the strips after the material to be tested-has dried is removed by this washing. Thereis thus provided a test strip having a permanent record of the time it has taken the material to be, tested to dry since the number of indentations per unit of time are known or may be calculated from the time it has taken the roller to'traverse a known length of The loose powder For a further exposition ofrmy invention reference maybe had to the annexed drawing and specification at the end whereof my invention will be specifically pointed out and claimed.

In the drawing,

Figure l is a plan view of the apparatus which forms a part of my invention.

- Figure 2 is a side elevation of the apparatus.

Figure 3 is a side elevation on an increased scale with a part of the rack broken away.

Figure 4 is an end view ,of the roller with part of the band cut away., I

1 Figure 5.is a detail showing a portion ofthe band, and

Figure 6 shows two test strips.

In the embodimentof my apparatus chosen for illustration in the drawing there is disclosed a rack 11 of wood or any suitable material having side walls 12. The upper surface of the rack is preferably made so as to slope slightly. Rack 11 is adapted to accommodate two or more test strips, such as strips 13 and 14 which are suitably made of long thin strips of sheet metal or ,glass but which may be of wood or paper or any desired substance. My apparatus also inrarsur'o -"rlcs Y cludes a, cylindrical roller 15 of sufficient length to fit neatly between the guides 12 of rack 11. Over the roller 15 there is provided a band 16 which may be made of rubber having projections or corrugations thereon extending parallel to the axis of the roller. The roller 15 has at its axis handles 1'7 to which are attached hooks 18 of the bail 19. Connected to bail 19 is cable 20 which at its other end winds on the shaft 21 of the clock Windlass 22. This clock Windlass is merely one means of providing motion for the roller 15 and, in the embodiment shown, consists of a clock with a suitable shaft 21 connected to the spindle which ordinarily carries the minute hand.

The method of performing my process of testing by use of the above described apparatus con sists in the following steps. First the material to be tested is applied to the testing strips as evenly as possible by means of a spatula or in any other convenient manner. The test strips 13 are then placed with their wet surfaces up on any convenient renewable surface, such as a newspaper, and the roller 15 is rolled over the surface of the strips without any pressure being applied to the roller. This provides a layer of the material to be tested on the strips and provides that this layer is very uniform in depth or thickness. The test strips are then placed side by side in the rack 11 and the band 16 is placed 'the material to be dried.

around the roller 15 at the lower end of the rack. If powder is to be applied to the band this is done before the band is placed around the roller by'dusting the powder on the band or by applying it to the band by means of a bag containing powder and known as painters pounce. The bail 19 is then attached to the handles 17 of roller 15 and to the clock Windlass which is then started. The roller 15 and the band 16 are thereby caused to slowly pass over the surface of the test strips 13 and 14. No further attention of the operator is required during this part of this process so that a single operator may make a large number of tests. At the end of the test periods, for example twenty-four hours, the test strips are removed from the rack. If no powder is used the strips will be found to contain the impression of the band 16 for a distance corresponding to the distance traversed by the roller 15 before the material to be tested dried, since after the material to be tested dried, the band 16 no longer made an impression on If, as is preferred, a powder is used the strips will .be found to be covered with bands of powder corresponding to the projections on the band 16. Examples of suitable powder for this purpose are flour, talc, chalk or any suitable powdered pigment The strips are then washed by flowing water across their surface and lightly rubbing the surface. This removes the powder which has not adhered to the material to be testedbefore the material dried. Since the rate of movement of the roller 15 is known or may be readily calculated from the time taken to traverse a known distance of 1. Apparatus for ascertaining the drying time of varnish and like products comprising in combination a fixed rack adapted to hold a strip having thereon a layer of the product, a turntable roller free'to progressively travel in respect to said fixed strip and adapted to roll a band onto the face of the quiescent product, and means for moving the roller along the rack the same distance per unit of time. I.

2, The method of ascertaining and recording the drying time of varnish and like products which consists in progressively rolling a band having a series of uniformly spaced transverse ribs at a uniform velocity and under uniform pressureonto the face of a fiat quiescent layer of the product, removing the band, and observing the effect of the'contact of the ribs of the band on the product.

. ALFRED M. PARKS. 

